Resonant recharge for synchronous pulsed laser operation
AssigneeSemiconductor Components Industries, LLC
InventorsJohn William WAGNER, Michael N. BORZA
Life of this patent
Estimating the term…
Abstract
Resonant recharge for synchronous pulsed laser operation. At least one example embodiment is a method of activating a laser diode, the method including: creating an oscillating voltage at a node between an inductor and a first capacitor, the oscillating voltage having a positive half-cycle and a negative half-cycle; charging a firing capacitor during a positive half-cycle of the oscillating voltage, the charging from the node and through a diode; and driving, during a negative half-cycle of the oscillating voltage, a pulse of current from the firing capacitance through a laser diode.
Claims20
A method of activating a laser diode, the method comprising:
- creating an oscillating voltage at a node between an inductor and a first capacitor, the oscillating voltage having a positive half-cycle and a negative half-cycle;
- charging a firing capacitor during the positive half-cycle of the oscillating voltage, the charging from the node and through a diode;
- and
- driving, during the negative half-cycle of the oscillating voltage, a pulse of current from the firing capacitor through the laser diode.
A driver integrated circuit for controlling activation of a laser diode, the driver integrated circuit comprising:
- a high-gate terminal, a low-gate terminal, a sense terminal, and a pulse-gate terminal;
- a resonance controller coupled to the high-gate terminal and the low-gate terminal, the resonance controller configured to assert the high-gate terminal for a first duration within a switching period, and configured to assert the low-gate terminal for a second duration within the switching period;
- and
- a firing controller coupled to the sense terminal and the pulse-gate terminal, the resonance controller configured to assert the pulse-gate terminal based on a signal sensed by way of the sense terminal.
A driver integrated circuit for controlling activation of a laser diode, the driver integrated circuit comprising:
- a source terminal, a switch-node terminal, a sense terminal, a ground terminal, and a pulse-gate terminal;
- a high-side field-effect transistor (high-side FET) defining a drain coupled to the source terminal, a source coupled to the switch-node terminal, and a gate;
- a low-side FET defining a drain coupled to the switch-node terminal, a source coupled to the ground terminal, and a gate;
- a resonance controller coupled to the gate of the high-side FET and the gate of the low-side FET, the resonance controller configured to assert the gate of the high-side FET for a first duration within a switching period, and configured to assert the gate of the low-side FET during a second duration within the switching period;
- and
- a firing controller coupled to the sense terminal and the pulse-gate terminal, the firing controller configured to sense an attribute of oscillation through the sense terminal, and assert the pulse-gate terminal based on the attribute of oscillation.
A system for light detecting and ranging, comprising:
- an inductor-capacitor circuit (LC circuit) defining a first lead, a second lead, and a charge node between an inductor and a capacitor;
- a high-side switch defining a first lead coupled to a power supply, a second lead coupled to the first lead of the LC circuit, and a control input;
- a low-side switch defining a first lead coupled to the first lead of the LC circuit, a second lead coupled to the ground, and a control input;
- a diode defining an anode coupled to the charge node, and a cathode;
- a firing capacitor defining a first lead coupled to the cathode of the diode, and a second lead coupled to the to the ground;
- a laser diode;
- a pulse-control switch coupled to the firing capacitor and the laser diode, the pulse-control switch configured to couple the firing capacitor to the laser diode based on a control input;
- a resonance controller coupled to the control inputs of the high-side switch, the low-side switch, and the pulse-control switch, the resonance controller configured to:
- create an oscillating voltage at the charge node by control of the high-side switch and the low-side switch, the oscillating voltage having a frequency, a positive half-cycle, and a negative half-cycle;
- and
- generate a laser pulse from the laser diode during the negative half-cycle of the oscillating voltage by making the pulse-control switch conductive.
Dependencies are inferred from the claim text.